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 * Copyright (c) 1997, 2013, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
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package javax.swing.border;

import java.awt.Graphics;
import java.awt.Insets;
import java.awt.Rectangle;
import java.awt.Component;
import java.io.Serializable;

/**
 * A class that implements an empty border with no size.
 * This provides a convenient base class from which other border
 * classes can be easily derived.
 * <p>
 * <strong>Warning:</strong>
 * Serialized objects of this class will not be compatible with
 * future Swing releases. The current serialization support is
 * appropriate for short term storage or RMI between applications running
 * the same version of Swing.  As of 1.4, support for long term storage
 * of all JavaBeans&trade;
 * has been added to the <code>java.beans</code> package.
 * Please see {@link java.beans.XMLEncoder}.
 *
 * @author David Kloba
 */
@SuppressWarnings("serial")
public abstract class AbstractBorder implements Border, Serializable {

  /**
   * This default implementation does no painting.
   *
   * @param c the component for which this border is being painted
   * @param g the paint graphics
   * @param x the x position of the painted border
   * @param y the y position of the painted border
   * @param width the width of the painted border
   * @param height the height of the painted border
   */
  public void paintBorder(Component c, Graphics g, int x, int y, int width, int height) {
  }

  /**
   * This default implementation returns a new {@link Insets} object
   * that is initialized by the {@link #getBorderInsets(Component, Insets)}
   * method.
   * By default the {@code top}, {@code left}, {@code bottom},
   * and {@code right} fields are set to {@code 0}.
   *
   * @param c the component for which this border insets value applies
   * @return a new {@link Insets} object
   */
  public Insets getBorderInsets(Component c) {
    return getBorderInsets(c, new Insets(0, 0, 0, 0));
  }

  /**
   * Reinitializes the insets parameter with this Border's current Insets.
   *
   * @param c the component for which this border insets value applies
   * @param insets the object to be reinitialized
   * @return the <code>insets</code> object
   */
  public Insets getBorderInsets(Component c, Insets insets) {
    insets.left = insets.top = insets.right = insets.bottom = 0;
    return insets;
  }

  /**
   * This default implementation returns false.
   *
   * @return false
   */
  public boolean isBorderOpaque() {
    return false;
  }

  /**
   * This convenience method calls the static method.
   *
   * @param c the component for which this border is being computed
   * @param x the x position of the border
   * @param y the y position of the border
   * @param width the width of the border
   * @param height the height of the border
   * @return a <code>Rectangle</code> containing the interior coordinates
   */
  public Rectangle getInteriorRectangle(Component c, int x, int y, int width, int height) {
    return getInteriorRectangle(c, this, x, y, width, height);
  }

  /**
   * Returns a rectangle using the arguments minus the
   * insets of the border. This is useful for determining the area
   * that components should draw in that will not intersect the border.
   *
   * @param c the component for which this border is being computed
   * @param b the <code>Border</code> object
   * @param x the x position of the border
   * @param y the y position of the border
   * @param width the width of the border
   * @param height the height of the border
   * @return a <code>Rectangle</code> containing the interior coordinates
   */
  public static Rectangle getInteriorRectangle(Component c, Border b, int x, int y, int width,
      int height) {
    Insets insets;
    if (b != null) {
      insets = b.getBorderInsets(c);
    } else {
      insets = new Insets(0, 0, 0, 0);
    }
    return new Rectangle(x + insets.left,
        y + insets.top,
        width - insets.right - insets.left,
        height - insets.top - insets.bottom);
  }

  /**
   * Returns the baseline.  A return value less than 0 indicates the border
   * does not have a reasonable baseline.
   * <p>
   * The default implementation returns -1.  Subclasses that support
   * baseline should override appropriately.  If a value &gt;= 0 is
   * returned, then the component has a valid baseline for any
   * size &gt;= the minimum size and <code>getBaselineResizeBehavior</code>
   * can be used to determine how the baseline changes with size.
   *
   * @param c <code>Component</code> baseline is being requested for
   * @param width the width to get the baseline for
   * @param height the height to get the baseline for
   * @return the baseline or &lt; 0 indicating there is no reasonable baseline
   * @throws IllegalArgumentException if width or height is &lt; 0
   * @see java.awt.Component#getBaseline(int, int)
   * @see java.awt.Component#getBaselineResizeBehavior()
   * @since 1.6
   */
  public int getBaseline(Component c, int width, int height) {
    if (width < 0 || height < 0) {
      throw new IllegalArgumentException(
          "Width and height must be >= 0");
    }
    return -1;
  }

  /**
   * Returns an enum indicating how the baseline of a component
   * changes as the size changes.  This method is primarily meant for
   * layout managers and GUI builders.
   * <p>
   * The default implementation returns
   * <code>BaselineResizeBehavior.OTHER</code>, subclasses that support
   * baseline should override appropriately.  Subclasses should
   * never return <code>null</code>; if the baseline can not be
   * calculated return <code>BaselineResizeBehavior.OTHER</code>.  Callers
   * should first ask for the baseline using
   * <code>getBaseline</code> and if a value &gt;= 0 is returned use
   * this method.  It is acceptable for this method to return a
   * value other than <code>BaselineResizeBehavior.OTHER</code> even if
   * <code>getBaseline</code> returns a value less than 0.
   *
   * @param c <code>Component</code> to return baseline resize behavior for
   * @return an enum indicating how the baseline changes as the border is resized
   * @see java.awt.Component#getBaseline(int, int)
   * @see java.awt.Component#getBaselineResizeBehavior()
   * @since 1.6
   */
  public Component.BaselineResizeBehavior getBaselineResizeBehavior(
      Component c) {
    if (c == null) {
      throw new NullPointerException("Component must be non-null");
    }
    return Component.BaselineResizeBehavior.OTHER;
  }

  /*
   * Convenience function for determining ComponentOrientation.
   * Helps us avoid having Munge directives throughout the code.
   */
  static boolean isLeftToRight(Component c) {
    return c.getComponentOrientation().isLeftToRight();
  }

}
